The present invention is directed to covers for the beds of pickup type trucks, open bed trailers, and recreational vehicles, such as small boats. In particular, the present invention is directed to cover systems employing a flexible cover, which may be fabricated from leather, fabric or vinyl, and attached to a plurality of rails which may be attached, in the example of a pickup truck, to the tops of the side walls of the cargo box of the pickup truck.
In order to support the cover, crossbars are employed which extend from one side of the truckbed to the other, and maintain the cover in an upwardly convex configuration, to facilitate runoff of rainwater, melted snow, dust and debris, so as to maintain an attractive appearance, and prevent accelerated degradation of the cover material. The first such crossbars to be used were simple flat, hollow, arcuate tubes which are substantially wedged by force into place, either onto stubs projecting from the clamps holding the rails in place, or into the rails themselves. Such simple crossbars tend to force the sidewalls of the truckbed outwardly, are difficult to install and remove, are inherently unstable in that they can twist or reverse themselves, and must have a relatively high arch in order to maintain the desired convex configuration.
Another example of crossbar construction may be found in the pickup truck bed cover system of Tucker, U.S. Pat. No. 5,152,574. In the Tucker '574 patent is disclosed a cover system in which a plurality of rails are clamped to the tops of the sidewalls of the cargo box of a pickup truck. The cover, such as previously described, may be attached to the rails by a plurality of male snap members which are clipped onto the outwardly facing surfaces of the rails. The cover has a plurality of female snap members affixed to the perimeter of the cover. Attachment of the crossbar members is accomplished by the bolting of the ends of the crossbar members to the tops of the clamping members which affix the rails to the sides of the truck.
While such a method of attachment may provide a relatively solid and secure attachment of the crossbar member to the rails of the cover system, if it is desired to place an object in the cargo box which is too large to be covered, and requires the removal of the crossbar members, it can be time-consuming, difficult or impossible to remove the crossbar members, especially if they are attached with bolts which may require a specialized or not readily available tool, such as an Allen wrench.
Other cover systems employ crossbar members which may have open forked ends, which fit around the threaded shafts of thumb-screw members which may be threaded into the clamping members or into the rails. An example of such a construction may be found in the TEKSTYLE TM brand cover system sold by Design Automotive Trim and Accessories, Inc. However, such other screw members, while possibly easier to manipulate than bolts requiring specialized tools, are still time-consuming to operate, and can loosen over time due to the vibrations of the moving vehicle which cause the crossbars to vibrate in turn, not only loosening the screws but also causing wear on the surfaces to which the ends of the crossbars are attached. In addition, the threads on the thumbscrews have a limited number of cycles of attachment and removal, before replacement is required.
Still another prior art cover system employs crossbar members which are provided with extension members which enable the cover system to accommodate truck beds having varying or non-standard widths. In Barben et al., U.S. Pat. No. 5,275,458, a cover system is disclosed, in which the crossbar members are substantially hollow tubes, of rectangular cross-section. Insert members 92 are provided which are insertingly received in crossbar members 28. Insert members 92 are hollow underneath so as to align with and receive tabular tangs 78, which project upwardly from the brackets 54 of clamps 24. Each of insert members 92 also includes a small tab, which aligns with and fits atop second leg 66, and both are received within and between the opposed edges defining the inwardly facing open slot of the rail member.
The Barben et al. '458 cover system, however, relies upon mere friction, of the tab and the second leg 66 within the slot, of the tangs 78, within the interior cavity of the insert members 92, and of the insert 92 within the opening of crossbar 28, in order to maintain crossbar members 28 in position. Such a method of attachment may be alternately too loose, and result in eventual displacement of the crossbars, or be too tight, and result in increased difficulty in removal of the crossbars, should that be desired.
It would be desirable to provide a flexible cover system for pickup truck cargo boxes and the like, which is provided with crossbar members which are readily attachable to and removable from the rails to which the flexible cover member is attached.
These and other objects of the invention will become apparent in light of the present specification, claims and drawings.